Polio eradication efforts may seem costlier than controlling the disease, but they will ultimately reduce costs and the number of cases, say researchers.

"The best deal from both a human health perspective and financially is to finish eradication," says Kimberly Thompson, of the US-based Harvard University School of Public Health and one of the authors of the research

The researchers calculated the cost of managing the disease versus eradicating polio in low-income countries.

They found that eradication results in fewer cases and offers lower cumulative costs. For poorer countries, eradication represents real savings within 20 years.

Efforts to totally eradicate the disease, however, have been unsuccessful, leading to suggestions that the World Health Organization (WHO) should change its polio strategy.

"[Some scientists] promised that we could save all the money and still have a low burden of disease, but we've shown that you can't do that," says Thompson.

Those who support the idea of control have underestimated the impact that scaling down immunisation programmes will have, she adds.

Thompson says that if immunisation in northern India was reduced by 10 per cent, there would be over 5000 additional cases a year in that region alone.

This is much higher than the number of cases considered reasonable under a control approach ― less than 500 globally ― by a 2006 paper in the journal Science.

Thompson and colleagues emphasise the need for immediate scaling up of efforts to wipe out polio, despite the widespread perception of an overly high cost.

"We are spending a lot of money on what looks like a small number of cases. But if you look at it with a short-term view and move resources to something else, you'll end up spending a lot more money and having a lot more cases," she says.

Bruce Aylward, Director of the Polio Eradication Initiative at the WHO, agreed, citing the human cost as a major motivator to continue with eradication.

"From a humanitarian perspective, the article demonstrates that the concept of 'effective control' is a false premise for a disease like polio," he says.

"A failure to finish eradication could result in up to four million paralysed children in low-income countries in 20 years," he adds.

Polio is endemic to Afghanistan, Egypt, India, Pakistan, Niger, Nigeria and Pakistan. The WHO puts the number of cases globally at around 2000 a year.